The New Pencil Urchin, also known as heterocentrotus mammilatus novus, is an evolution of the New Pencil Urchin after 250 million years. Heterocentrotus mammilatus is Latin name for "pencil urchins" while novus means "new" in Latin. Although its appearance may remain the same, many aspects of its body have been modified and developed slightly due to the changes of its habitat geographically and also the years of environmental pressure. It has grown bigger in size, with a 5 inch diameter and a height of 9.2 centimetres; slightly larger than the Red Slate Pencil Urchin by 2 inches in its diameter and 3 centimetres shorter.
Scientific Classification
Level
Classification
Kingdom
Animalia
Phylum
Echinodermata
Class
Echinoidea
Order
Echinoida
Family
Echinometridae
Genus
Heterocentrotus
Species
H. mammilatus novus
Habitat
Geographical location
According to research and studies, 250 million years ago all the continents on Earth were joined together creating the supercontinent which was named Pangea. While humans set foot on Earth, the continents have been experiencing continental drift. 250 million years later, the continents have reunited together into the ultimate supercontinent, conveniently named Pangea ultima. Referring to figure 2, Hawaii, where the new pencil urchin still resides in (marked in the red circle) has drifted closer to North America and away from Asia. It is now at the far east of the Pacific Ocean. It is believed that some new pencil urchins may have slowly drifted into the seas of North America, possibly creating a new species of sea urchin.
Climate
Due to global warming, the massive continent on Earth would still be suffering from extraordinary temperatures during summer and in places like Hawaii, winter would literally feel like winter. This negatively affects the habitat of the new pencil urchin because they are sensitive to sunlight and they prefer living in cooler water. Intense sunlight may also harm the kelp forests and affects new pencil urchins directly as kelp are their main source of food.
Prey and predators
Sea otter holding onto a sea urchin
Having drifted to a larger group of continents, the new pencil urchins may have set foot on a new group of predators’ territory. Sea otters don’t used live anywhere near Hawaii, however being so close to North America mean they will encounter with sea otters, as they reside in Canada, meaning that the new pencil urchin will have a new group of predators. Other new predators that were not found in Hawaii would also include the titan triggerfish and the wolf eel as well as other marine animals that live on the coast of North America.
Adaptations
Behavioural Adaptation #1
Red slate pencil urchins may live in the same area but they weren’t known to hunt together as a group. Most of the time, red slate pencil urchins are attracted to food in a large group however they do not hunt together. Today, new pencil urchins form a small group of 5 – 8 urchins. They usually hunt and rest with these groups and occasionally these small groups may join up with other small groups against larger predators.
This behaviour helps the new pencil urchins as this decreases the risks of being attacked by predators. Also, when new pencil urchins come face to face with big-sized predators like triggerfish or wolf eels, it is more convenient if they are in a big group that can defend themselves and overcome the predators.
The environmental pressure that may have caused this adaptation would possibly be due to the drift of the continents on Earth because this brings in more foreign sea animals into the new pencil urchin habitat. This then requires the new pencil urchin to devise new methods in protecting itself and sustaining their population.
Behavioural Adaptation #2
Female red slate pencil urchins allowed their eggs to float freely in the ocean until it becomes fertilized and develops into a blastula embryo. However, today the new pencil urchin prefers to hold onto their eggs with their spines. Other species of sea urchins were known to do this too.
New pencil urchins do this because it provides them with a greater degree of protection.
The environmental pressure that may have caused this adaptation would again be due to the arrival of foreign animals causing the new pencil urchins to protect themselves.
Structural Adaptation #1
The red slate pencil urchin’s mouth consisted of 5 large and strong teeth used to bore out holes and chew on kelp. However the new pencil urchin has 10 teeth. The original 5 teeth, which consist of strong minerals like calcite, remain but in between its gums are smaller teeth that also have the same minerals as the larger teeth except they are smaller in size (refer to figure 2).
These 5 smaller teeth help the new pencil urchin because it adds an extra net of defense. Red slate pencil urchins were often attacked by trigger fish because they knew how to eat it by penetrating the soft tissue (refer to figure 2) surrounding the mouth and reach inside its body. Often the teeth aren’t much of a help but the smaller teeth would prick the triggerfish when it tries to penetrate the soft tissue.
As well as defense, this new set of teeth would also make creating holes out of rocks more efficient for the new pencil urchin and would also open a wider range of food source for the new pencil urchin as its teeth are strong enough to eat other animals in its habitat such as small fishes.
Environmental pressure that could have given rise to this adaptation would be how the red slate pencil urchin was once a great part of the triggerfish’s diet. As it has always been attacked by many species of triggerfish, this new set of teeth may be the response of defending itself.
Structural Adaptation #2
The red slate pencil urchin was known to have 3 tube feet on one side next to its mouth. These 3 tube feet weren’t used much for walking; instead it was used to grip on to kelp or other food sources. The new pencil urchin has developed to have 4 feet; 2 on each side of its mouth (refer to figure 3). These 4 tube feet are each 3cm long, which are slightly longer than the tube feet of the red slate pencil urchin.
With 2 feet at each side, the new pencil urchin has a better sense of balance and as it can be seen in figure 3, it is stubbier and longer than the tube feet of the red slate pencil urchin. This means that it is able to support the weight of a new pencil urchin making it possible for the new pencil urchin to walk a bit on the sea floor. However, a new pencil urchin is somewhat heavy which is why the new pencil urchin cannot walk very quickly.
Environmental pressure that may have resulted in the development of the new pencil urchins’ tube feet may be due to the change of its habitat. When global warming continued throughout the years, even after humans were wiped out, the new pencil urchins’ habitat was modified and it became uncomfortable with the sea temperature thus causing it to travel away from the intense heat in Hawaii.
Physiological Adaptation
The red slate pencil urchin is not venomous, however the new pencil urchin has developed a poisonous fluid in some of it spines near its aboral area and its oral area. Similar to the purple sea urchin (and several other venomous sea urchins), when the spine is touched by a predator, it releases the poisonous fluid and injects it into the predator’s body. The predator will then feel numbness and would be unable to attack.
This adaptation can help the new pencil urchin by protecting it as it can ward off predators. However, new pencil urchins don’t usually attack their predators; it normally stays still to defend themselves before they get attacked. This means that in one way or another, the urchin would have some damage caused to its body, usually a broken spine. It is fortunate in a way because the new pencil urchin can regenerate broken spines if it’s not too harshly damaged.
Environmental pressure that resulted to this adaptation can be being consistently attacked by predators that are much larger in size thus being much more powerful. This includes wolf eels, sea otters, triggerfish and sometimes birds. By gaining this ability to release poison, new pencil urchins would no longer be easy prey in the coral reefs.
APOD (Astronomy Picture of the Day). (2007). Pangea Ultima: Earth in 250 million years? Retrieved 20th of July, 2010, from http://apod.nasa.gov/apod/ap070922.html
The New Pencil Urchin, also known as heterocentrotus mammilatus novus, is an evolution of the New Pencil Urchin after 250 million years. Heterocentrotus mammilatus is Latin name for "pencil urchins" while novus means "new" in Latin. Although its appearance may remain the same, many aspects of its body have been modified and developed slightly due to the changes of its habitat geographically and also the years of environmental pressure. It has grown bigger in size, with a 5 inch diameter and a height of 9.2 centimetres; slightly larger than the Red Slate Pencil Urchin by 2 inches in its diameter and 3 centimetres shorter.
Scientific Classification
Level
Classification
Kingdom
Animalia
Phylum
Echinodermata
Class
Echinoidea
Order
Echinoida
Family
Echinometridae
Genus
Heterocentrotus
Species
H. mammilatus novus
Habitat
Geographical location
According to research and studies, 250 million years ago all the continents on Earth were joined together creating the supercontinent which was named Pangea. While humans set foot on Earth, the continents have been experiencing continental drift. 250 million years later, the continents have reunited together into the ultimate supercontinent, conveniently named Pangea ultima. Referring to figure 2, Hawaii, where the new pencil urchin still resides in (marked in the red circle) has drifted closer to North America and away from Asia. It is now at the far east of the Pacific Ocean. It is believed that some new pencil urchins may have slowly drifted into the seas of North America, possibly creating a new species of sea urchin.
Climate
Due to global warming, the massive continent on Earth would still be suffering from extraordinary temperatures during summer and in places like Hawaii, winter would literally feel like winter. This negatively affects the habitat of the new pencil urchin because they are sensitive to sunlight and they prefer living in cooler water. Intense sunlight may also harm the kelp forests and affects new pencil urchins directly as kelp are their main source of food.
Prey and predators
Having drifted to a larger group of continents, the new pencil urchins may have set foot on a new group of predators’ territory. Sea otters don’t used live anywhere near Hawaii, however being so close to North America mean they will encounter with sea otters, as they reside in Canada, meaning that the new pencil urchin will have a new group of predators. Other new predators that were not found in Hawaii would also include the titan triggerfish and the wolf eel as well as other marine animals that live on the coast of North America.
Adaptations
Behavioural Adaptation #1
Red slate pencil urchins may live in the same area but they weren’t known to hunt together as a group. Most of the time, red slate pencil urchins are attracted to food in a large group however they do not hunt together. Today, new pencil urchins form a small group of 5 – 8 urchins. They usually hunt and rest with these groups and occasionally these small groups may join up with other small groups against larger predators.
This behaviour helps the new pencil urchins as this decreases the risks of being attacked by predators. Also, when new pencil urchins come face to face with big-sized predators like triggerfish or wolf eels, it is more convenient if they are in a big group that can defend themselves and overcome the predators.
The environmental pressure that may have caused this adaptation would possibly be due to the drift of the continents on Earth because this brings in more foreign sea animals into the new pencil urchin habitat. This then requires the new pencil urchin to devise new methods in protecting itself and sustaining their population.
Behavioural Adaptation #2
Female red slate pencil urchins allowed their eggs to float freely in the ocean until it becomes fertilized and develops into a blastula embryo. However, today the new pencil urchin prefers to hold onto their eggs with their spines. Other species of sea urchins were known to do this too.
New pencil urchins do this because it provides them with a greater degree of protection.
The environmental pressure that may have caused this adaptation would again be due to the arrival of foreign animals causing the new pencil urchins to protect themselves.
Structural Adaptation #1
The red slate pencil urchin’s mouth consisted of 5 large and strong teeth used to bore out holes and chew on kelp. However the new pencil urchin has 10 teeth. The original 5 teeth, which consist of strong minerals like calcite, remain but in between its gums are smaller teeth that also have the same minerals as the larger teeth except they are smaller in size (refer to figure 2).
These 5 smaller teeth help the new pencil urchin because it adds an extra net of defense. Red slate pencil urchins were often attacked by trigger fish because they knew how to eat it by penetrating the soft tissue (refer to figure 2) surrounding the mouth and reach inside its body. Often the teeth aren’t much of a help but the smaller teeth would prick the triggerfish when it tries to penetrate the soft tissue.
As well as defense, this new set of teeth would also make creating holes out of rocks more efficient for the new pencil urchin and would also open a wider range of food source for the new pencil urchin as its teeth are strong enough to eat other animals in its habitat such as small fishes.
Environmental pressure that could have given rise to this adaptation would be how the red slate pencil urchin was once a great part of the triggerfish’s diet. As it has always been attacked by many species of triggerfish, this new set of teeth may be the response of defending itself.
Structural Adaptation #2
The red slate pencil urchin was known to have 3 tube feet on one side next to its mouth. These 3 tube feet weren’t used much for walking; instead it was used to grip on to kelp or other food sources. The new pencil urchin has developed to have 4 feet; 2 on each side of its mouth (refer to figure 3). These 4 tube feet are each 3cm long, which are slightly longer than the tube feet of the red slate pencil urchin.
With 2 feet at each side, the new pencil urchin has a better sense of balance and as it can be seen in figure 3, it is stubbier and longer than the tube feet of the red slate pencil urchin. This means that it is able to support the weight of a new pencil urchin making it possible for the new pencil urchin to walk a bit on the sea floor. However, a new pencil urchin is somewhat heavy which is why the new pencil urchin cannot walk very quickly.
Environmental pressure that may have resulted in the development of the new pencil urchins’ tube feet may be due to the change of its habitat. When global warming continued throughout the years, even after humans were wiped out, the new pencil urchins’ habitat was modified and it became uncomfortable with the sea temperature thus causing it to travel away from the intense heat in Hawaii.
Physiological Adaptation
The red slate pencil urchin is not venomous, however the new pencil urchin has developed a poisonous fluid in some of it spines near its aboral area and its oral area. Similar to the purple sea urchin (and several other venomous sea urchins), when the spine is touched by a predator, it releases the poisonous fluid and injects it into the predator’s body. The predator will then feel numbness and would be unable to attack.
This adaptation can help the new pencil urchin by protecting it as it can ward off predators. However, new pencil urchins don’t usually attack their predators; it normally stays still to defend themselves before they get attacked. This means that in one way or another, the urchin would have some damage caused to its body, usually a broken spine. It is fortunate in a way because the new pencil urchin can regenerate broken spines if it’s not too harshly damaged.
Environmental pressure that resulted to this adaptation can be being consistently attacked by predators that are much larger in size thus being much more powerful. This includes wolf eels, sea otters, triggerfish and sometimes birds. By gaining this ability to release poison, new pencil urchins would no longer be easy prey in the coral reefs.
Sea Urchin of the Past
Sea Urchin of the Present
Sea Urchin of the Future
BibliographyEnchantedLearning.com. (2010). Sea Urchin. Retrieved 20th of July, 2010, from http://www.enchantedlearning.com/subjects/invertebrates/echinoderm/Seaurchin.shtml
Ocean Research Group. (2010). Echinoderms: The Spiny Animals! Retrieved 20th of July, 2010, from http://www.oceanicresearch.org/education/wonders/echinoderm.html
PetEducation.com. (2010). Slate Pencil Urchin. Retrieved 20th of July, 2010, from http://www.peteducation.com/article.cfm?c=16+2158+2220&aid=2130
APOD (Astronomy Picture of the Day). (2007). Pangea Ultima: Earth in 250 million years? Retrieved 20th of July, 2010, from http://apod.nasa.gov/apod/ap070922.html